In many electronics applications, an analog input signal is converted to a digital output signal (e.g., for further digital signal processing). For instance, in precision measurement systems, electronics are provided with one or more sensors to make measurements, and these sensors may generate an analog signal. The analog signal would then be provided to an analog-to-digital converter (ADC) as input to generate a digital output signal for further processing. In another instance, an antenna generates an analog signal based on the electromagnetic waves carrying information/signals in the air. The analog signal generated by the antenna is then provided as input to an ADC to generate a digital output signal for further processing.
ADCs can be found in many places such as broadband communication systems, audio systems, receiver systems, etc. ADCs can translate analog electrical signals representing real-world phenomenon, e.g., light, sound, temperature or pressure for data processing purposes. Designing an ADC is a non-trivial task because each application may have different needs in performance, power, cost and size. ADCs are used in a broad range of applications including communications, energy, healthcare, instrumentation and measurement, motor and power control, industrial automation and aerospace/defense. As the applications needing ADCs grow, the need for accurate and reliable conversion performance also grows.
Generally speaking ADCs are electronic devices that convert a continuous physical quantity carried by an analog signal to a digital number that represents the quantity's amplitude (or to a digital signal carrying that digital number). An ADC is typically composed of many devices making up an integrated circuit or a chip. An ADC is usually defined by the following application requirements: its bandwidth (the range of frequencies of analog signals it can properly convert to a digital signal), its resolution (the number of discrete levels the maximum analog signal can be divided into and represented in the digital signal), and its signal to noise ratio (how accurately the ADC can measure signal relative to the noise the ADC introduces). ADCs have many different designs, which can be chosen based on the application requirements. In many cases, it is not trivial to design an ADC that meets the application requirements while providing adequate performance.